qemu-kvm/kvm-target-s390x-kvm-pv-Provide-some-more-useful-informa.patch

From c1273f9e38f81f912cd2bd1dd4a43f9652766f76 Mon Sep 17 00:00:00 2001
From: Thomas Huth <thuth@redhat.com>
Date: Wed, 10 Jan 2024 15:29:16 +0100
Subject: [PATCH 5/5] target/s390x/kvm/pv: Provide some more useful information
 if decryption fails
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RH-Author: Thomas Huth <thuth@redhat.com>
RH-MergeRequest: 348: s390x: Provide some more useful information if decryption of a PV image fails
RH-Jira: RHEL-18214
RH-Acked-by: Jon Maloy <jmaloy@redhat.com>
RH-Acked-by: Cédric Le Goater <clg@redhat.com>
RH-Commit: [5/5] 087acaecfaa5921b409beb212123214fa79fe50c

JIRA: https://issues.redhat.com/browse/RHEL-18214

commit 7af51621b16ae86646cc2dc9dee30de8176ff761
Author: Thomas Huth <thuth@redhat.com>
Date:   Wed Jan 10 15:29:16 2024 +0100

    target/s390x/kvm/pv: Provide some more useful information if decryption fails

    It's a common scenario to copy guest images from one host to another
    to run the guest on the other machine. This (of course) does not work
    with "secure execution" guests since they are encrypted with one certain
    host key. However, if you still (accidentally) do it, you only get a
    very user-unfriendly error message that looks like this:

     qemu-system-s390x: KVM PV command 2 (KVM_PV_SET_SEC_PARMS) failed:
      header rc 108 rrc 5 IOCTL rc: -22

    Let's provide at least a somewhat nicer hint to the users so that they
    are able to figure out what might have gone wrong.

    Message-ID: <20240110142916.850605-1-thuth@redhat.com>
    Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
    Reviewed-by: Cédric Le Goater <clg@redhat.com>
    Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com>
    Signed-off-by: Thomas Huth <thuth@redhat.com>

Conflicts:
    target/s390x/kvm/pv.c
    target/s390x/kvm/pv.h
    (contextual conflict due to missing async-teardown in RHEL8)
Signed-off-by: Thomas Huth <thuth@redhat.com>
---
 hw/s390x/ipl.c             |  5 ++---
 hw/s390x/ipl.h             |  2 +-
 hw/s390x/s390-virtio-ccw.c |  5 ++++-
 target/s390x/kvm/pv.c      | 25 ++++++++++++++++++++-----
 target/s390x/kvm/pv.h      |  5 +++--
 5 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index c25e247426..c6cefdd3fe 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -709,7 +709,7 @@ static void s390_ipl_prepare_qipl(S390CPU *cpu)
     cpu_physical_memory_unmap(addr, len, 1, len);
 }
 
-int s390_ipl_prepare_pv_header(void)
+int s390_ipl_prepare_pv_header(Error **errp)
 {
     IplParameterBlock *ipib = s390_ipl_get_iplb_pv();
     IPLBlockPV *ipib_pv = &ipib->pv;
@@ -718,8 +718,7 @@ int s390_ipl_prepare_pv_header(void)
 
     cpu_physical_memory_read(ipib_pv->pv_header_addr, hdr,
                              ipib_pv->pv_header_len);
-    rc = s390_pv_set_sec_parms((uintptr_t)hdr,
-                               ipib_pv->pv_header_len);
+    rc = s390_pv_set_sec_parms((uintptr_t)hdr, ipib_pv->pv_header_len, errp);
     g_free(hdr);
     return rc;
 }
diff --git a/hw/s390x/ipl.h b/hw/s390x/ipl.h
index dfc6dfd89c..f9cce33330 100644
--- a/hw/s390x/ipl.h
+++ b/hw/s390x/ipl.h
@@ -107,7 +107,7 @@ typedef union IplParameterBlock IplParameterBlock;
 
 int s390_ipl_set_loadparm(uint8_t *loadparm);
 void s390_ipl_update_diag308(IplParameterBlock *iplb);
-int s390_ipl_prepare_pv_header(void);
+int s390_ipl_prepare_pv_header(Error **errp);
 int s390_ipl_pv_unpack(void);
 void s390_ipl_prepare_cpu(S390CPU *cpu);
 IplParameterBlock *s390_ipl_get_iplb(void);
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 7bfa5b4e8f..94434c3bb1 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -374,7 +374,7 @@ static int s390_machine_protect(S390CcwMachineState *ms)
     }
 
     /* Set SE header and unpack */
-    rc = s390_ipl_prepare_pv_header();
+    rc = s390_ipl_prepare_pv_header(&local_err);
     if (rc) {
         goto out_err;
     }
@@ -393,6 +393,9 @@ static int s390_machine_protect(S390CcwMachineState *ms)
     return rc;
 
 out_err:
+    if (local_err) {
+        error_report_err(local_err);
+    }
     s390_machine_unprotect(ms);
     return rc;
 }
diff --git a/target/s390x/kvm/pv.c b/target/s390x/kvm/pv.c
index e14db4f41a..ae75063777 100644
--- a/target/s390x/kvm/pv.c
+++ b/target/s390x/kvm/pv.c
@@ -27,7 +27,8 @@ static bool info_valid;
 static struct kvm_s390_pv_info_vm info_vm;
 static struct kvm_s390_pv_info_dump info_dump;
 
-static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
+static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data,
+                         int *pvrc)
 {
     struct kvm_pv_cmd pv_cmd = {
         .cmd = cmd,
@@ -44,6 +45,9 @@ static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
                      "IOCTL rc: %d", cmd, cmdname, pv_cmd.rc, pv_cmd.rrc,
                      rc);
     }
+    if (pvrc) {
+        *pvrc = pv_cmd.rc;
+    }
     return rc;
 }
 
@@ -51,12 +55,13 @@ static int __s390_pv_cmd(uint32_t cmd, const char *cmdname, void *data)
  * This macro lets us pass the command as a string to the function so
  * we can print it on an error.
  */
-#define s390_pv_cmd(cmd, data) __s390_pv_cmd(cmd, #cmd, data)
+#define s390_pv_cmd(cmd, data) __s390_pv_cmd(cmd, #cmd, data, NULL)
+#define s390_pv_cmd_pvrc(cmd, data, pvrc) __s390_pv_cmd(cmd, #cmd, data, pvrc)
 #define s390_pv_cmd_exit(cmd, data)    \
 {                                      \
     int rc;                            \
                                        \
-    rc = __s390_pv_cmd(cmd, #cmd, data);\
+    rc = __s390_pv_cmd(cmd, #cmd, data, NULL); \
     if (rc) {                          \
         exit(1);                       \
     }                                  \
@@ -108,14 +113,24 @@ void s390_pv_vm_disable(void)
      s390_pv_cmd_exit(KVM_PV_DISABLE, NULL);
 }
 
-int s390_pv_set_sec_parms(uint64_t origin, uint64_t length)
+int s390_pv_set_sec_parms(uint64_t origin, uint64_t length, Error **errp)
 {
+    int ret, pvrc;
     struct kvm_s390_pv_sec_parm args = {
         .origin = origin,
         .length = length,
     };
 
-    return s390_pv_cmd(KVM_PV_SET_SEC_PARMS, &args);
+    ret = s390_pv_cmd_pvrc(KVM_PV_SET_SEC_PARMS, &args, &pvrc);
+    if (ret) {
+        error_setg(errp, "Failed to set secure execution parameters");
+        if (pvrc == 0x108) {
+            error_append_hint(errp, "Please check whether the image is "
+                                    "correctly encrypted for this host\n");
+        }
+    }
+
+    return ret;
 }
 
 /*
diff --git a/target/s390x/kvm/pv.h b/target/s390x/kvm/pv.h
index 9360aa1091..6868c3f4ac 100644
--- a/target/s390x/kvm/pv.h
+++ b/target/s390x/kvm/pv.h
@@ -41,7 +41,7 @@ static inline bool s390_is_pv(void)
 int s390_pv_query_info(void);
 int s390_pv_vm_enable(void);
 void s390_pv_vm_disable(void);
-int s390_pv_set_sec_parms(uint64_t origin, uint64_t length);
+int s390_pv_set_sec_parms(uint64_t origin, uint64_t length, Error **errp);
 int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak);
 void s390_pv_prep_reset(void);
 int s390_pv_verify(void);
@@ -60,7 +60,8 @@ static inline bool s390_is_pv(void) { return false; }
 static inline int s390_pv_query_info(void) { return 0; }
 static inline int s390_pv_vm_enable(void) { return 0; }
 static inline void s390_pv_vm_disable(void) {}
-static inline int s390_pv_set_sec_parms(uint64_t origin, uint64_t length) { return 0; }
+static inline int s390_pv_set_sec_parms(uint64_t origin, uint64_t length,
+                                        Error **errp) { return 0; }
 static inline int s390_pv_unpack(uint64_t addr, uint64_t size, uint64_t tweak) { return 0; }
 static inline void s390_pv_prep_reset(void) {}
 static inline int s390_pv_verify(void) { return 0; }
-- 
2.41.0